Tread-surface.



N9. 880,862. PATENTED MAR. 3, 1908.

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No. 880,862. PATENTED MAR. 3, 1908.

R. G. CHASE.

TREAD SURFACE.

APPLICATION FILED JUNE 2. 1906.

RODNEY G. CHASE, OF MEDFORD, MASSACHUSETTS.

TREAD-SURFACE.

Specification of Letters Patent.

Patented March 3, 1908.

Application filed June 2. 1906. Serial No. 319.831.

leave interstices between the strips when.

they are assembled, and thereby ermitting dust, dirt and snow to pass throug the tread surface.

' The invention relates more especially to the manner of attaching the contacting surfaces of adjacent strips so as to firmly hold them together when the strips are in their desired relative positions and locked, but

which will keep their locking means in nection between the contacting'surfaces of proper relative dpositions and still allow of a united longitu inal movement of one strip relative to the next strip of the series, as is the case when the series of strips is bent orcurved so as to form surfaces with other than straight side edges, as in car steps which are sometimes made with the front edge curved.

The invention consists of the novel construction, arrangement and combinations of parts, as will be fully described hereinafter and particularly set forth in the claims annexed hereto, and it is carried out substantially as illustrated on the accompanying drawings which form an essential part of this specification, and whereon like characters of reference refer to like parts wherever they occur on the dilferent parts of the drawings.

On the drawings: Figure 1 represents a plan view of a rectangular tread surface showing one preferred manner of making my improved tread surface. Fig. 2 represents a plan view of a tread surface made in a similar manner to that shown in Fig. 1, but showing such surface as having one of its side edges curved, as would be the case when the surface was applied to a carstep with a curved front edge. Fig. 3 represents a plan view of another arrangement of my improved tread surface, showing the same ma e rectangular in outline. Figs. 4, 5, 6,7; 8, 9 and 10 represent detail views of the means of conthe adjacent strips used in my improved tread surfaces, showing different means which may be employed to fasten or hold the strips together and still allow of longitudinal movement of one strip relative to the next stri without defeating the action of the fastening devices.

Heretofore in the formation of tread surfaces from strips of metal arrange-d edgewise to the surface and crim ed or bent so that portions of one strip wil come into contact with thenext strip and leave interstices between other portions of the strips, it has been the practice to provide the contacting surfaces with correspondingly shaped proje'otions and depressions, usually spherical, Which projections and depressions fit each other and are intended to prevent any movement of the surface of one strip upon the contacting surface of another strip, when the series of strips forming the tread surface has been clamped or otherwise held in its assembled position. These projections and depressions have usually been made by indenting one side of the strip, thus forming a depression on that side of the strip, and at the same time forcing the metal of the strip at this place outward on the opposite side thereof, thus forming a correspondingly shaped projection from this latter side of the strip. As these projections and de ressions are usually made spherical they ave in clined surfaces which tend to defeat their obj ect, if there is any looseness in the clamping or holding device from wear, or from any other cause; as the projection will easily slip out from its corresponding depression and allow one strip to move vertically upon the surface of the other strip, causing the strips to separate, and destroying the tread surface. It has also been ascertained, when other than a straight edge was necessary in the outline of the tread surface, that one or more {of the strips near such curved edge has to be cut shorter than the other strips used, owin to the inability to curve the strips and still fieep the strips locked together by the projections on one strip entering the depressions on the other stri The use of these shorter strips, with this method of locking them together, prevents their ends from being properly held and fastened.

. It is the object of present invention to obviate the above mentioned defects and to form the strips in such a manner that they willbe prevented from moving vertically out curved form to correspond with the curved edge of the outline of the tread surface which they are to constitute, leaving no short strips and insecurely locked ends to cause the strips to become separated.-

1 My improved tread surface consists of a series of thin metal strips 1 which is crimped or bent into any desired, but preferably uniformshape, so that portions of the surface of one strip will contact with the surface of the next adjacent strip, when the strips are assembled to form a tread surface. The strips have been shown as bent into two different shapes forming two difierent designs of tread surfaces on the drawin s. These strips are arranged so that their t in edges will be presented to the wear or the tread portion of the surface.

Referring to the arrangement of my invention as shown in Figs. 1, 2, 4, 5 and 6, the strips have been provided with a perforation 2 and projection 3 at all of the portions of the strips which contact with. portions of the other and next adjacent strips. The perforations have been formed by punching a portion of the metal from the strip, leaving it attached to the strip at one side only and so that the portion punched out may be turned outwards and form the projections 3, as shown more clearly in Figs. 4, 5 and 6. The projections 8 may be made somewhat longer than the thickness of the metal whichis used in forming the strips and from which the projections are made, and these projections are of a width substantially equal to the vertical dimension of the perforations so as to allow the projections to move in said perforations longltudinally to the strip, but to prevent a transverse or vertical movement of one strip relative to the next strip into which it is looked as hereinafter described. The perforations and projections on one strip are made in such relation to the perforations or projections on the other strip that they "interlock each other, as shown in Figs. 4, 5 and 6. The projections on each strip pass through the perforations on the adjacent strips and, as the perforations have a uniform dimension vertically but are elongated beyond the.

thickness of the. projections, it will be seen that each strip is free',to move longitudinally in relation to the next strip, but as the vertical dimensions of the perforations and the projections are equal to each other, it will be seen that there will be no vertical movement ofeither of the strips relative to the other strips. This freedom, of the strips to move longitudinally in relation to each other, allows the series of strips used in the formation of the tread surface to be bent into curved form, when the surface to be formed has a curvededge or edges, and it also causes all of the contacting portions of the istrips to be firmly locked to each' other, as shown in Fig. 3

After the series of strips has been assembled and adjusted into its proper relative position the strip may be fastened together y turning the portions of the projections 3, whichg-ertend beyond the opposite surface of the interlocked strips, downward against the said surface, substantially as shown in detail in Fig. 5. It will be seen, that by this means the entire series of strips may be firmly locked and fastened together so as to prevent any vertical or transverse move? ment of .the stri s relative to each other; thus preventing t e breaking up of the tread surface formed from the strips. It will also be understood that it is not necessary to turn down all of the projections and fasten all of the contacting portions of the strips in order to kee the strips assembled, as everysecond, thir fourth, of fifth set of projections only might be turned downward and still cause the desired result.

The series of strips 1, after being properly assembled, may be inserted into an inner binding or frame 'made from a strip 4, to which the tread surface is attached by'means of the projections 3, in a manner similar to the locking and fastening of the series of strips together above described, and also that this inner frame may be surrounded by a second strip of metal 5 forming an outer' other moisture should be ke t out ,of the joint between'the innerand t e outer bindings of the tread surface, either or both of the stri s 4 and 5, from which such bindings are ma e, may be provided with a channel of sufficient depth to receive the turned over ends of the rojections 3 by which the binding is attac ed to the tread surface, and by this means the adjacent surfaces of the bindings may be brought very close together making a joint between them which maybe v painted or galvanized and made perfectly tight.

of the series of strips 7 has been shown as being different from that of the strips 1 shown in t e other views of the drawin The strips 7 are provided with elongate perfo- In Figs. 3 and'7 the design of the crimping rations 8 at their contacting surfaces, substantially similar to'the perforations 2 in the strips lbut there are no locking projections corres onding to the projections 3 shown in the other views. In the place of the locking projections being attached to the strip, I use rods .9 or strips 10, or a combination of rods and strips, which extend through the perforations in the strips and are secufed to the frame or binding by being riveted to the frame or otherwise secured thereto, and by this means I am able to firmly fasten and lock the stri s in their proper assembled positions. If Fuse stri s 1.0 to 'lock and fasten the strips together, may turn the portion of the strip 10, which is within the interstice between the series of the strips 7, and by this means prevent the strips 7 from moving on the strips 10 out of their proper places. The ends of the strips 10 are turned downward outside of the inner binding or frame or are otherwise secured to the frame so as to hold the entire tread surface assembled.

The perforations 8 in the stri )s 7 are of a length somewhat longer than t e thickness of the rods or strips by which the series of strips is fastened together, and theyare of a Width equal to the vertical dimension of the fastening rods or stri s. By this construction of the tread su ace, as shown in Figs. 3 and 7, it will be seen that I am able to accomplish substantially the same results as can be accomplished by the construction shown and described in relation to Figs. 1 and 2.

In Figs, 1, 2, 4, 5 and 6 I have shown each of the contacting surfaces of each strip as being provided with a perforation and a projection to interlock each other and hold the strips assembled. shown the strips as being provided with only perforations at their contactin surfaces and ave provided rods or bolts to old the strips assembled, but it is not necessary that either of these constructions should be used in order to carry out my invention and I have also shown other arrangements of the interlocking perforations and projections in Figs. 8 to 10 mclusive.

In Figs. 8 and 9, the contacting surface on one side of each strip is provided with perforations 2 while the contacting surface in the opposite side of each strip, excepting where a fastening rod 9 is used to hold them together, is provided with projections 3 to enter the perforations in the contacting surface of the next strip of the series. By this construction each strip is made a duplicate of the other strip and when the strips are assembled they may be fastened and held in their assembled positions either by turning the projecting ends of the projections down against the sides of the opposite strips or by means of the rods 9 the latter having been shown on the drawing.

In Figs. 3 and 7 I have In Fig. 10, I have shown the strips as consisting of two series, one series being pro vided with perforations 2 only, while the other series is provided with projections 3 only, excepting where the rods 9 are used .to hold the strips assembled and the strip of one series alternating with those of the other series of strips, Wlll enter the perforations in the other series of strips. These strips may be held assembled by turning the projections downward against the other strips or by means of the rods 9, such rods having been shown on the drawing.

By positively locking the strips together as above described it will be seenthat I entirely eliminate any liability of the strips moving vertically out of pro er relation to eachother, and can therefore eep the tread lowing of a limited longitudinal movement of the strips relative to each other while they are being adjusted into place, I am able to vary the direction of each strip from astraight line without disarrangement of the interlocking of their locking and fastening devices, and can therefore apply my improved. tread surface to surfaces having other than straight edges and canaccomplish this without having to use shortened strips with their ends unlocked and liable to become separated from the other strips to which they should be locked.

By the use ofmy improved tread surface, and more especially the construction of the same as shown in Figs. 1 and 2, there are comparatively no pro ecting edges or parts which dust and dirt might gather and, by cole lecting moisture, tend to rust and ruin the tread surface, but on the contrary the entire tread surface has clear passages through it by.

which the dust, dirt and other things which come upon the top of the surface will pass through the interstices between the stri s and leave the same clean and so that it Wlll dry quickly without rusting.

Having thus fully described the nature, construction and the operation of my invention, I wish to secure by Letters Patent and to claim:

1.- A tread surfaceof the class described, consisting of a series of crimped thin metal strips arranged edgewise to the surface and leaving interstices between the strips when assembled, locking means to hold the strips assembled with portions of the surface of each strip contacting with portions of the surface of the next strip of the series, and perforations through the contacting portions of the strips, receiving the locking means and allowing of longitudinal movement of one strip relative to the adjacent strip.

2. A tread surface of the class described,

consisting of a series of crim ed thin metal strips arranged edgewise to t e surface and leaving interstices between the strips when assembled, perforations and projections which interlock each other arranged at portions of the surface of the strip which contact with portions of. the surface of the next adjacent stri of the series, the projections fitting the perfbrations vertically and preventing movement of the strips in that direction relative to each other and the erforations of sufficient length longitudinal y to allow of a longitudinal movement of each strip relative to the next strip, whereby the general direction of the strips may be changed from a straight line, and means to hold the series of the strips assembled.

3. A treadsurface of the class described, consisting of a series of crim ed thin metal strips arranged edgewise to tl fe surface with portions of the surface of each stri contacting with portions of the'surface o the next adjacent strip of the series, leaving interstices between the strips when assembled, perforations and projections on the contacting portions of the stri s, which perforations and projections inter ock each other and prevent vertical displacement of the strips when assembled.

4. A tread surface of the class described, consisting of a series of crimped thin metal strips arranged edgewise to the surface with 7 portions of the surface of each strip contacting with portions of the surface of the next adjacent strip of the series, leaving interstices between the strips when assembled, perforations and projections on the contacting portions of the strips, which perforations and projections interlock each other and prevent vertical displacement of the strips when assembled and the projections extending through the perforations with their ends turned against the opposite surface of the strip to fasten the series of strips in proper assembled positions.

5. A tread surface of the class described, consisting of a series of crimped thin metal strips arranged edgewise to the surface leaving interstices between the strips when assembled, perforations and projections on the to lock said strips against vertical displacement, combined with an inner metal binding to which the strips are locked, and an outer metal binding secured to the inner binding and covering the locking means between the strips and the inner binding.

7. A curved-edge tread surface, composed .of a series of crimped thin metal strips ar-- ranged edgewise to the surface, leaving interstices between the strips and having portions of'the surface of each strip in contact with portions of the surface of the next adjacent strip, projections and perforations which interlock each other arranged on said contacting surfaces but which are adjustable longitudinally in relation to each other allowing the contacting surfaces to move longitudinally one upon the other, and means to hold said strips assembled whereby the general direction of said strips'is caused to conform substantially to the curve of the edge of the tread surface and all of the strips are firmly locked together their entire length.

In testimony whereof I have affixed my signature, in presence of two witnesses.

RODNEY G. CHASE. Witnesses:

HENRY CHADBOURN, NELsoN CURTIS. 

